1. Field of the Invention
The present invention relates to a flame retardant rubber-reinforced styrene-based resin composition having an excellent impact resistance.
2. Description of the Prior Art
Recently, with various laws and regulations for fire prevention, a flame retardant rubber-reinforced styrene-based resin represented by an acrylonitrile-butadiene-styrene-based copolymer (hereafter abbreviated as ABS resin) has widely been used in fields such as domestic electrical appliances and office-automation devices.
As a method for imparting flame retardance to the rubber-reinforced styrene-based resin, the combined use of a bromine flame retardant and antimony trioxide is known, wherein, depending on necessary flame retardance and mechanical property, the type and quantity of the bromine flame retardant and the quantity of antimony trioxide have been selected, but there has been a problem that the elevation of flame retardance lowers the mechanical property.
To elevate flame retardance, as a bromine flame retardant, the combination of a carbonate oligomer of tetrabromobisphenol-A and tetrabromobisphenol-A (Japanese non-examined Patent Publication No. 60-192761), or the combination of a carbonate oligomer of tetrabromobisphenol-A, tetrabromobisphenol-A and polydibromophenyleneoxide (Japanese non-examined Patent Publication No. 58-38746) have been proposed.
Though by these methods the flame retardance was elevated, there was a drawback that the impact resistance, particularly the surface impact resistance important in practical use, was lowered.